Computer system having reversible bus connectors

1. A bus, having: at least two parallel bus lines, and at least a first and a second connector having a same pinout, each connector having a plurality of terminals extending generally along a first direction, the plurality of terminals comprising at least two bus-terminals each connected to one bus line, and at least one non-bus terminal not connected to a bus line, wherein the first connector is an image of the second connector, rotated through 180 degrees about an axis perpendicular to the first direction, with this image rotation mapping each bus terminal of the second connector to a respective bus terminal of the first connector, and mapping a predetermined non-bus terminal of the second connector to a predetermined non-bus terminal of the first connector, said predetermined non-bus terminals being electrically connected.

2. A bus according to claim 1, wherein the image in the rotation of one given terminal having a given logic level is a terminal having an opposite logic level.

3. A bus according to claim 1 wherein all terminals of a connector are on one side of the bus lines.

4. A computer board comprising a bus according to claim 1, said at least on non-bus terminal of each connector comprising power and ground terminals.

5. A circuit board, comprising a connector with at least two connector terminals; and a switching arrangement having connector-side terminals connected to said connector terminals, chip-side terminals, and a control input; said switching arrangement mapping the chip-side terminals to the connector-side terminals under control of said control input.

6. A circuit board according to claim 5, wherein said control input is connected to a connector terminal.

7. A circuit board according to claim 5, wherein said switching arrangement comprise two buffers, the terminals of each buffer being connected to the connector-side terminals and to the chip-side terminals, a signal received on said control input enabling either one of said two buffers.

8. A combination of a computer board and a circuit board, the computer board comprising a bus, the bus having: at least two parallel bus lines, at least a first and a second connector having the same pinout, each connector comprising at least two bus-terminals each connected to one bus line, and at least one non-bus terminal not connected to a bus line, wherein the first connector is the image rotated through 180 degrees of the second connector with this image rotation mapping each bus terminal of the second connector to a respective bus terminal of the first connector, and mapping a predetermined non-bus terminal of the second connector to a predetermined non-bus terminal of the first connector, said predetermined non-bus terminals being electrically connected, said at least one non-bus terminal of each connector comprising power and ground terminals, the circuit board comprising: a connector with at least two connector terminals; and a switching arrangement having connector-side terminals connected to said connector terminals, chip-side terminals, and a control input; said switching arrangement mapping the chip-side terminals to the connector-side terminals under control of said control input.

9. A computer board with a bus having parallel bus lines and a least two identical connectors, each connector having a plurality of terminals extending generally along a first direction, and at least two identical circuit boards, each connected to one of said connectors, wherein one connector is the image of another connector rotated through 180 degrees about an axis that is perpendicular to the first direction, and wherein the circuit boards connected to said one connector and said another connector are relatively shifted in a direction perpendicular to the first direction and perpendicular to the axis of rotation.

10. A process for routing signals on a motherboard to at least one circuit board connected in one connector of a series of identical connectors in alternate directions, each connector having a plurality of terminals extending in spaced relation generally along a first direction, adjacent connectors being the image of neighboring connectors, rotated through 180 degrees about an axis perpendicular to the first direction, the method comprising the steps of: routing the signals along parallel bus lines to the connectors, thus changing the mapping of the terminals of the connectors to the bus lines between connectors in alternate directions; and switching the signals received on each circuit board according to the direction of the connector, so as to have an identical mapping of the switched signals to the bus lines, whatever the direction of the connector.

11. process according to claim 10, wherein the direction of a connector is determined in a circuit board according to the polarity of a given terminal of the circuit board connector.

12. A process according to claim 10, wherein the step of switching comprises: storing the signals in a first buffer, in a given order; storing the signals in a second buffer, in a different order; and reading the signals from one of said first and second buffers.